Welcome to the Community, @tribaltemplemerc. I've got the steps to help resolve your concern.
The account's country is already set where the subscription was made. In your case, there isn't a way to directly change your QuickBooks Self-Employed (QBSE) US to the Australia (AU) region.
First, I'd suggest creating a new QBSE company for AU. Then, cancel the existing US account to avoid any duplicate charges. I'll guide you through the process below.
To create a new company:
- Go to this link: https://quickbooks.intuit.com/au/self-employed/.
- Scroll down to the bottom of the page where you can click the Buy Now or Free 30-day trial button.
- Click Sign In under Already have a QuickBooks Self-Employed account?.
- Enter your existing Intuit login credentials.
- Choose Sign in.
- Follow the on-screen instructions to set up the account.
The screenshot below shows you the first three steps.

Once done, you'll have to print any necessary reports or export transactions to Excel from your QBSE US account. These will serve as your future reference on your AU company. When you're ready, that's the time to cancel it.
Lastly, I recommend visiting this website: QBSE AU. It provides you with video tutorials to help you get started and efficiently manage your mileage, invoices, expenses, receipts, GST, and bank accounts.
I'll be glad to lend a helping hand if you need anything else. Wishing you and your business continued success while using QuickBooks, @tribaltemplemerc.